added link to hello world

nrf52-stepper/index.html

@@ -21,6 +21,8 @@ pre code {
 
 <p>Some sample firmware is available below (or as files: <a href='nrf52-drv8825/nrf52-drv8825.ino'>nrf52-drv8825.ino</a> and <a href='nrf52-drv8825/radio.h'>radio.h</a>).  This code defines a command set issued over the radio for moving a number of steps, changing stepping speed, setting microstepping parameters, and setting a current limit value.</p>
 
+<p>For help getting started programming the nRF52, see <a href='https://gitlab.cba.mit.edu/pub/hello-world/nrf52'>this page.</a></p>
+
 <pre>
 <code>
 #include "radio.h"